Device for adjusting the components of a chair

ABSTRACT

The invention relates to a device for adjusting a first component of a chair, in particular an office chair, with respect to a second component of the chair, the said device being provided with a latching unit by means of which one of the two components can be arranged in different positions with respect to the other component. The latching unit has a guide path which is arranged on the first component. A latching element is provided on the other component, it being possible for the latching element to be arranged in the guide path in latching positions which predetermine the positions of one component with respect to the other component. In order to obtain a functionally reliable latching procedure using a device of this type, it is proposed that the guide path ( 40 ) is of essentially groove-shaped design at least in the region of the latching positions, and the latching element ( 45 ) is guided in the groove-shaped guide path ( 40 ).

The invention relates to a device for adjusting one component of a chair, in particular an office chair, with respect to another component of the chair, the device being provided with a latching unit by means of which one of the two components can be arranged in positions, which can be changed in latching steps, with respect to the other component, the latching unit having a guide path which is arranged on one of the two components and on the other component a latching element is provided which can be arranged in the guide path in latching positions which predetermine positions of one component with respect to the other component.

In the case of chairs, it is often desirable to be able to arrange certain components, for example the backrest of a chair, in different positions. By this means, the intention is to be able to adapt the chair to the users body so as to make an ergonomically favourable seat position possible for the user.

In this connection, the publication WO-A 98/09553 discloses a device for regulating the height of the backrest, in which the backrest which can be adjusted in height relative to a seat plate is arranged on a fixed support element. The support element comprises a guide part which is orientated in the vertical direction and in profile cross section is of approximately U-shape design, a grid rail which is arranged in the said guide part and a sliding rail which is guided displaceably in the guide part and also a spring element which can be brought into engagement with it. The spring element as two contact arms which can be brought into engagement with the two toothed arrangements of the grid rail, which are arranged lying opposite the spring element and are each open on one side, the said contact arms, when the backrest is raised, latching in any desired position into the toothed arrangement as a consequence of the spring-elastic restoring force. With this device, the backrest can also be adjusted upwards from the particular position. In particular due to the relatively great length of the contact arms and their undefined movement options there is the risk of them being easily deformed and/or of the ends of the contact spring changing their position. Both possibilities, however, mean that satisfactory guidance of the contact arms in the toothed arrangement can no longer be ensured and adjustment of the backrest is no longer possible.

The invention is therefore based on the object of improving a device of the type mentioned in the introduction to the effect that a functionally reliable latching procedure between two components of the chair, in particular of a backrest with respect to a seat body, can be provided using relatively simple structural means.

In the case of a device according to the prechraracterizing clause of Claim 1, this object is achieved in that the guide path is of essentially groove-shaped design at least in the region of the latching positions, and the latching element is guided in the groove-shaped guide path. Since the latching element itself does not have to be acted upon by a force, but is intended to be forcibly guided by the profile of the guide path, a particularly functionally reliable guidance of components of a chair is possible. In addition, unlike in WO-A 98/09553, just one latching element is required in devices according to the invention. The reduction to fewer moveable components has a positive effect on the functional reliability of the device and makes possible a compact arrangement and simple installation.

It has proven expedient if the groove of the guide path is of a width which permits only slight play of the latching element with regard to directions transverse to the course of the guide path. At least in the region of the latching section, the groove should therefore be only slightly wider then a width of the latching element. This means that the guidance between the latching element in the guide path with regard to the instantaneous direction of relative movement between the latching element in the guide path has essentially just one degree of freedom, namely the possibility of relative movement of the latching element in the guide path in the direction of the course of the guide path. The latching element can therefore be guided in an essentially form-fitting manner, as a result of which long lasting reliable guide elements can be achieved in a structurally particularly simple manner.

In a further preferred embodiment of the invention, the latching element can be designed as a pivotable lever which has a latching pin which is arranged in the guide path. The pivot-mounting enables, in a structurally particularly simple and functionally reliable manner, the latching element to be guided in the guide path and thus relative movement to be produced between the latching element and the guide-path element.

It is particularly preferred if the device according to the invention is used for adjusting the height of a backrest of an office chair. However, it is equally possible to use the device according to the invention to make it possible for other chair components to be adjusted, for example an arm rest of a chair to be adjusted with respect to the seat surface. Other examples include adjustment of the seat depth of the backrest with respect to the seat surface or else adjustment of the seat height of the sea surface with respect to a base of the chair.

Further preferred embodiments of the invention emerge from the dependent claims.

The invention is explained in greater detail with reference to an exemplary embodiment which is illustrated schematically in the figures, in which:

FIG. 1 shows an office chair, which is illustrated in schematic view, having a backrest unit formed from a backrest support and a height-adjustable backrest;

FIG. 2 shows the backrest unit illustrated in a view according to the arrow direction X sketched in FIG. 1, with the backrest support and the backrest;

FIG. 3 shows the backrest unit illustrated in plan view and in section according to the line III-III sketched in FIG. 2;

FIG. 4 shows the backrest unit illustrated in section according to the line IV-IV sketched in FIG. 3;

and

FIG. 5 shows a section according to the line V-V in FIG. 4 with a latching unit which is arranged, for example, on the backrest support and is intended for adjusting the height of the backrest.

FIG. 1 shows a chair which is illustrated in a schematic view, in particular an office chair 10 which can be adjusted in respect of height and inclination in a manner which is not illustrated. The office chair 10 has a base frame 15 which is provided, for example, with a plurality of supporting arms 11 and castors 12 amounted thereon and has a central vertical pillar 14 and a gas-filled compression spring 13 arranged therein. Mounted at the upper end of the tubular vertical pillar 14 is a first supporting body 20 which is operatively connected to the gas-filled compression spring 13 and designed in the form of a cantilever in the direction towards a knee side of the chair. Furthermore, a second supporting body 19 which is arranged on the first supporting body 20 can be seen, as can a backrest unit which is arranged thereon and is denoted in its entirety by 75. The second supporting body 19 is mounted on the first supporting body by means of a rotating/sliding bearing 20′.

Two bearing brackets 16 and 17, which are arranged spaced apart from each other transverse to the seat direction, are respectively fastened in the knee-side region of the first supporting body 20 and in the backrest-side region of the second supporting body 19. The bearing brackets 16 and 17 are used for holding and fastening a seat body 18 (illustrated schematically) by means of rotating bearings 16′ and 17′ which are respectively arranged on the knee side and backrest side and by means of which a respective pivot axis is formed. The seat body 18, the first supporting body 20, the second supporting body 19 and the backrest unit 75 which is arranged on the latter can therefore be pivoted with respect to one another, as a result of which different inclinations of the seat body 18 and the backrest unit 75 can be achieved. The backrest unit 75, which is illustrated schematically in FIG. 1, comprises a backrest support 30 which is arranged and fastened on the second supporting body 19, and a backrest 25 which is arranged on the backrest support.

By means of an appropriately designed latching unit 35, the backrest 25 can be adjusted in height, for example starting from a first basic position illustrated in FIG. 1, stepwise in latched steps relative to the seat body 16 in the arrow direction H and can be returned back into the basic position rectilinearly in one step over the entire adjusting distance in accordance with the arrow direction H′. However, in another embodiment which is not illustrated, provision could also be made for the backrest 25 to be guided from an upper position stepwise in latched steps according to the arrow direction h′ in the direction of the seat body 18 and for it to be returned from the lower position rectilinearly into the upper position in the arrow direction H.

FIG. 2 shows the backrest unit in a view according to the arrow direction X sketched in FIG. 1. This illustration shows the backrest support 30 which is arranged on the second supporting body 19 and is arranged with an upper subsection in a recess 24 of approximately pocket-shaped design in the backrest 25. In the exemplary embodiment which is illustrated, the backrest 25 is in engagement with the latching unit 35, which is arranged in the backrest support 30 and in the backrest 25 and is illustrated schematically in FIGS. 1 and 2, in such a manner that raising of the backrest 25 causes the latching unit to be adjusted stepwise relative to the seat body 18 in the arrow direction H and to be returned from an upper end position into a lower one in the arrow direction H′.

In FIG. 3, an exemplary embodiment of the backrest unit 75 is Illustrated in section and in plan view according to the line III-III sketched in FIG. 2. The backrest support 30, a subsection of the backrest 25, a plate-shaped supporting part 50 which is designed as a retaining element and is connected to the backrest 25, and a guide-path element 35′ arranged on the supporting part 50 and forming part of the latching unit 35 can be seen here. The backrest unit 75, together with the individual elements 25, 30, 35 and 50, is explained in greater detail below.

In the exemplary embodiment illustrated in FIG. 3, the backrest 25 comprises a back wall 23 and an end wall 22 spaced apart therefrom. The end wall 22 is divided into two subsections 22′ and 22″ so as to form the pocket-shape recess 24. The sub sections 22′ and 22″ are connected to the back wall 23 in the region of the recess 24 by means of walls 21 and 21 ′ which are integrally formed on them. The recess 24 which is arranged on the end side 22 of the back rest 25 is open downwards towards the seat surface 18 and is used to hold the supporting part 50 and the backrest support 30 which is partially arranged therein.

The backrest support 30 which his illustrated in FIG. 3 and is of approximately U-shaped design in profile cross section has an end wall 31 and limbs 26 and 26′ arranged laterally thereon. Provided on the mutually facing inner sides of the two limbs 26 and 26′ are respective grooves 27 and 27′ which essentially run rectilinearly and are bounded by first webs 28, 28′ and second webs 29, 29′ which are arranged parallel to one another.

The supporting part 50 which is illustrated in profile cross section in FIG. 3 and is arranged in the recess 24 of the backrest 25 comprises a plate 51 which is provided on one side with a plurality of ribs 52 which are spaced apart from one another and are connected to the backrest 25. Integrally formed on the two opposite ends of the plate 51 are respective webs 53 and 53′ which are or L-shaped or backwards L-shaped design in profile cross section and respectively engage in one of the two grooves 27, 27′. A groove 55 or a web 32 of the backrest support 30 is provided on the plate 51 of the supporting part 50, between two webs 54 and 54′ on the side which faces the inner side of the end wall 31. The webs 53, 53′, 32 guide the backrest 25 longitudinally in the grooves 27, 27′ D 55 in its adjustment direction. Regarding a Width of the supporting part 50, the guide-path element 35′ is integrally formed approximately in the centre of the supporting part and on its side facing the backrest support 30.

Furthermore, a lever arm 45, which has a spindle body 45 at one end and a latching pin 47 at the other end, is arranged on the backrest support 30 opposite the guide-path element 35′ as latching element. The lever arm 45 is mounted in the backrest support 30 in a manner such that it can pivot freely by the spindle body 46 around its (imaginary axe) Axis Y (see also FIG. 4). The lever arm is operatively connected to the guide-path element by means of the latching pin 46 which engages in the guide-path element 35′ (FIGS. 3, 4).

In FIG. 4, the backrest unit 75 is illustrated in section according to the line IV-IV sketched in the region of the recess 24 in FIG. 3. The pivoting lever 45 which is mounted with the spindle body 46 on the backrest support 30 and engages in a groove-shape guide path 40 by means of the latching pin 47 can also be seen here.

FIG. 5 shows in more detail the guide-path element 35′ which is illustrated in sectional view according to the incepting line V-V in FIG. 4 and, in the exemplary embodiment which is illustrated, is arranged on the wall 51 of the supporting part 50. FIG. 5 furthermore shows the pivoting lever 45 which is mounted on the spindle body 46 together with the latching pin 47 which is arranged on the said lever and is positioned in a latching stop 44.2 of the guide path 40. FIG. 5 furthermore schematically illustrates, by means of the arrows 1 and 2 and the “dash-dotted” lines which are not numbered, the sequence or movement of the latching pin 47 caused by adjusting the height of the backrest 25.

The guide-path element 35′ is bounded laterally by the first webs 33 and 33′ (FIG. 3) and at the upper and lower end by second webs 34 and 34′ (FIG. 4). Furthermore, the guide-path element 35′ is provided with the self-contained, groove-shaped guide path 40. The guide path 40 has a latching section 41′ and a return section 41″ which are connected to each other at their upper and lower ends by means of likewise groove-shaped deflecting paths 42 and 48 to form a self-contained path. Except for the return section 42, a width of the guide path 40 is only slightly larger than the diameter of the latching pin. In addition, as can be seen from FIG. 5, the pivotable lever arm 45 of the latching element is substantially shorter than the longitudinal extent of the return section (41″).

The latching section 41′ and the return section 41″ are arranged spaced apart from each other and functionally separated from each other by means of an intermediate piece 36 which is orientated parallel to the longitudinal extent of the two sections 41′ and 41″.

The latching section 41′ of the groove-shaped guide path 40 is provided, on the side which faces the web 33′, with a plurality of latching stops 44, 44.1-44.5 which are arranged spaced apart from one another and are connected to one another by a plurality of groove-shaped curved paths having a double curve. In the exemplary embodiment illustrated in FIG. 5, the latching section 41′ comprises the latching stops which are arranged one behind another the longitudinal course of the latching section and are denoted by 44; 44.1; 44.2; 44.3; 44.4 and 44.5, and also the curved path which connect the said latching stops to one another and are denoted by 43; 43.1; 43.2; 43.3 and 43.4.

Each curved path 43, 43.1-43.5 has a projection 39, 39.1-39.4 which is formed on he web 33′ and in incliner in the adjustment direction. Between the respective latching stop 44, 44.1-44.5 and the respective projection 39, 39.1-3.9.4 the latching pin executes with respect to the guide-path element 35′ a curved relative movement which is orientated in the clockwise direction in the guide-path 40. Each segment, corresponding to one latching step, of the latching section 41′ has a deflecting toe 38; 38.1; 38.2; 38.3 and 38.4 between a projection and the next latching stop 44.1-44.5 in each case. The deflecting toes are integrally formed on the intermediate piece 36. The contour of the deflecting toes 38; 38.1; 38.2; 38.3 and 38.4 in each case ends an anticlockwise, second, curved relative movement of the latching pin 47 with respect to the guide-path element 35′. An end piece of each deflecting toe is inclined in the manner of a ramp towards the adjustment direction H.

The lever 45 therefore pivots in two opposite directions during a latching step. Starting from a latching stop, during movement towards the respectively next latching stop the latching pin 47 is first of all situated on one side of the line 60 along which the pivoting axis Y moves during an adjustment movement of the backrest 25. A projection 39, 39.1-39.4 of a segment of the latching section 41′ causes the latching pin 47 then to pivot by means of a pivoting movement around the axis Y onto the other side of the line 60. The approximately S-shaped profile of each segment subsequently leads to an opposite pivoting movement of the latching pin 47 back to the original side of the line 60. As soon as the latching pin strikes against the deflecting toe 38, 38.1-38.4 of a segment of the latching section 41′, the deflecting-toe contour, which rises in a ramped-like manner counter to the adjustment direction, causes the adjustment movement in the adjustment direction of the backrest to stop. By means of a slight movement of the backrest counter to the adjustment movement, the Latching pin can be transferred, by continuing its pivoting movement, into the next latching 44.1-44.5. This is indicated in FIG. 5 by the arrow, 61 which reproduces the relative movement, corresponding to this, of the latching pin from the particular deflecting toe to the next latching stop.

By this means, the backrest has taken up a further intermediate position in which it has been adjusted upwards by one latching step. In this position, in which the latching pin is fixed in the latching stop 44, 44.1-44.5, in an undercut formed by the projection 39, 39.1-39.4, the backrest remains on the latching pin 47 because of its own weight. FIG. 5 shows this by way of example for the latching stop 44.2 which defines an intermediate position between a lower latching position (predetermined by the latching stop 44) and an upper latching position (predetermined by the latching stop 44.5) of the backrest.

Starting from the latching stop 44.5, the latching pin can be transferred via the deflecting section 48, the return section 41″ and the further deflecting section 42 back to the beginning of the latching section 41′, namely the latching stop 4A (arrow 2). During this movement, the backrest is displaced from its upper latching position to its lower latching position.

In another exemplary embodiment which is not illustrated it would also be possible to arrange the guide-path element on the backrest support and the lever on the backrest. The effect which could be achieved by this is that it would be possible for the backrest to be displaced downwards in latching steps and to be returned in a single step from its lowest position into its upper starting position.

The guide-path element 35′ which is described above in conjunction with the individual figures and the arrangement thereof on a backrest or on a backrest support is not restricted to the exemplary embodiments which have been illustrated and described. Further expedient embodiments and arrangements are also possible without departing from the basic concept of the invention. 

1. Device for adjusting a first component of a chair, in particular an office chair, with respect to a second component of the chair, the said device being provided with a latching unit by means of which one of the two components can be arranged in different positions with respect to the other component, the latching unit having a self-contained guide path which is arranged on the first component and on the other component a latching element being provided which has a latching pin (47) and can be arranged in the guide path in latching positions which predetermine the positions of one component with respect to the other component, the guide path (40) being of essentially groove-shaped design at least in the region of the latching positions, and the latching pin of the latching element (45) being guided in the groove-shaped guide path (40), characterized in that the latching element is a lever (45) which can pivot freely around a spindle body (40).
 2. Device according to claim 1, characterized in that the guidance between the latching element (45) and the guide path (40) has just one degree of freedom and the latching positions of the latching element (45) are arranged in a latching section (41′) of the guide path (40), the latching element (45) beina guided in an essentially form-fitting manner in the latching section (41′).
 3. Device according to one or both of the preceding claims, characterized in that the groove-shaped guide path (40) is provided with a return section (41″) 2nd a latching section (41′), and the return section (41″) and the latching section (41′) are connected to each other by two deflecting paths (42, 48), as a result of which the guide path is self-contained.
 4. Device according to one or more of the preceding claims 2 to 3, characterized in that the latching segment (41′) has a plurality of latching positions of the latching segment, which positions are connected to one another in each case by essentially identical segments of the guide path (40).
 5. Device according to one or more of the preceding claims, characterized in that the guide path (40) is arranged on a guide-path element (35′) which is connected to one of the components, and this component is guided rectilinearly on the other component of the chair.
 6. Device according to claim 5, characterized in that the segments have a doubly curved profile.
 7. Device according to one or more of the preceding claims, characterized in that it is provided for adjusting the height of one component with respect to the other component.
 8. Device according to claim 7, characterized in that the latching element (45) is arranged on a support of the chair and the guide path (40) is arranged on a backrest which is moveable with respect to the support.
 9. Device according to one or more of claims 4 to 8, characterized that the two sections (41′, 41″) are spaced apart from one each other by means or an intermediate piece (36) which is orientated in the longitudinal direction of the said sections, a plurality of deflecting toes (38 and 38.1 to 38.4) which are spaced apart from each other being integrally formed on the intermediate piece (36) on the side which faces the latching section (41′).
 10. Device according to claim 9, characterized in that the deflecting toes (38 and 38.1 to 38.4) are designed and integrally formed on the intermediate piece (36) in such a manner that the latching pin (47) can be brought automatically into engagement with the particular latching stop (44 and 44.1 to 44.4).
 11. Device according to claims 1 and 5, characterized in that the spindle body (46) of the freely pivotable lever (45) is arranged opposite the guide-path element (35′).
 12. Device according to claims 1 and 3, characterized in that the pivotable lever (45) is substantially shorter than the longitudinal extent of the return section (41″). 